Centering-punch.



0. GHRIS'IENSON.

GENTEBING PUNCH.

APPLICATION FILED APR.12, 1913.

. MTNEEEEE www Patented Nov. 18, 1913.

' dent of Milwaukee, in the county of lilik OSCAR CHRISTENSN, @IlMILWAUKEE', WISCGESN,

Pate/need hier.. il d.

To all 'wlw/m, t may concern:

Be it, known that L, Oficina Cinnaminson, a citizen. ol. the UnredStates, and a reeb- Waukee and State of Ytlieconein, have in vent-ed newand useful Improvements in Centering-l'lunches, of which the following;is a description, reference 'being had' to the accompanying drawings,which are a part el" this speeilication.

This invention relates to centering punches for laying out werk for theboring machineend has for its object to sinipliiy the operation offorming guide marks for centering the drill.

Heretofore it has been customary in laying out Work for the lio-ringmachine to surround the point indicating the center of the opening to bedrilled with four other points on cross lines through the center point,such four points being measH ured with thedividers so as to heequidistant from the center point and then more clearly 'marked with aprick punch to serve as a guide for centering the drill. The firstContact of tin; drill with the Work ohliterates the center marl( so thatif the position of the Work with relation io the drill is not accuratethe four equi-distant marks from the center point, indicate that fact hyshowing the circle being cut by the drill to be .nearer to Sonie pointsthan the others, ylChis enables the operator to withdraw the drill andchange the position of the Work 'with relation to it. until the circle othe cut of the drill appears to he. at the same distance from all of thefour guide marke, when it is known that the Work is in proper positionwith relation to the tool to have the openk ing accurately drilledtherein. This oper' tion of marking theV cross linee, measuring' theequi-distant `guide marke and punching' them requires considerable timeand if not carefully done admits oit more or less in accuracy,

The object of the present .invention is to dispense with the .necessityfor this careful measurement. and provide a tool which Will produce thefour guide .marks accuratelyv pceitioued equi-distant from the centermark by a. single quick operation, as simple as the making of thecenterl niark itself.

.Another object of this intention is to perfect details o1c constructionci" a centen mg punch of this character.-

yofi; Fie 3 cate the saine parte ii different riens: 1 Figure l in aisectional :ation ot a certer- -1ng punch construct;r1

accordance :h this invention; Fig. 2 in an end View there m. is a ViewShow h the Annrh in operet-ien, -the Work l enig e ,ctioned to chowmarke yproduced by the punch; hier. Li is a perepecri're `rien' of thepunch tar" fr blocks handed. iogether readjj..7 for in the clamping heitolf the princi and. Fig. is e View ig the nrfi prode-iced 'by the punchnl? this invern-1 i. In ehese drawings lll indicate.; n shank having ahead lll. which termi; in a flat face l2 and ie surrounded hy clampingholt 13. The clamping hell; ifi of flexible sheet, metal. preferably hrewith its lower part. which extends beyond the face of the punch headslotted part Wav around and having` projecting care il ci nectcd hy aclamping screw 15 for contract-- ing it around a set oit clamping blocksio. The clamping` blocks il; have parallel side walls forming hearing*guides by which they Slide in radial grooves provided for thorn in acroseehnpetfl centerpiece l? and the centerpiece with the clampingfhloelis sembled forms a cylindrical hotly to r. within the cylindricalclan'ipingx heh' lil. 1 At the center ol' the cenierpioce l? filiere isQG an openingsA through which a center. pin passes. there being a headlll) at the end of the center 'pin W` li enters .les in the punch head.containing n coil ssprinlv Q() which hears on the head of the center pinto prees it ou tnardljr. hutpermirting il'. to recede. rl'he inner de etthe clamping' blocks i6 are preferably stepped forma tion and theopenings oit' the centerpiece in which they iti are c'orreepondirgflj'Y.shaped and are .notched or groom-.id 'to 'forni clamp-V ing sente atvarious dist-annee from the eenter pin i8 to receive punch pine ill-which are of the saine length and pointed on their outer endewhiletheir inner ende bear against the fiat face ol ihelllmch head. ln any ofthe corresponding' positions of Atheii punch pins they arediaxnetrically dormire each other und. equidietantfrom the center pin 18and the clamping action oi une i 'ing belt 13, serves to clamp themrigidly in place by pressure against the clamping blocks 16. Forconvenience in handling the clamping blocks and centerpiece when retheclamping belt they are provided With a groove which extends entirelyaround the cylindrical body and a split ringor retaining band 22'itsWithin this groove and vholds the parts together though 'permitting oftheir being readily separated if desired.

In operation it is only necessary to insert the center pin 18 in therecess iormed by the prick punch at the point Where the opening isdesired and a hammer when the four punch pins 21 will be driven into theWork and produce the guide marks equi-distant from the center mark foruse in the same manner as before in properly positioning the drill Withrelation tothe Work to produce the opening at the desired point.

A material saving in time is eected by the use of this tool and the Workis more accurately done, for the position of the punch pins in anyadjustment thereoi` may be more accurately determined than by theordinary method and. these positions being lined apply to all operationsof the tool..

When it is desired to alter the adjustment of the punch pins 4for use inmarking the Work for larger or smaller drills it is only necessary toloosen the clamping bolt 15 and Withdraw the punch pins 21 from onenotch and insert-thern in another. 'lf a correspending adjustment ismade in allor .the pins they will always remain equi-distant from thecenter pin and diametrically opposits each other throughout theiradjustments for different sizes of drill openings.

lVhat I claim as new and desire to secure by Letters Patent is:

1. centering punch, comprising 'a punch body, a. center pin thereon,said punch body having punch pin seats vpositioned around the center pinequi-distant therefrom with radial openings leading thereto, punch pinsitting 'in the punch .pin seats,` clamping blocks slidably mounted inthe radial openings and bearing against the punch pins, and a clampingmember surrounding the punch body and engaging -the clamping blocks forforcing them against the punch pins.

2. A centering punch, comprising a punch then strike the shank llhwithbody, a centering pin*` thereon, there being a plurality of series ofgrooves in the punch body forming punch pin seats around the center pinwith the respective punch pin seats of each series at differentdistances from the center pin and the corresponding punch pin seats or"distant fromv the Ycenter pin, there being radial openings in the punchbody leading to the respective series of punch4 pin seats, punch pinsfitting in corresponding punch in seats of` the several series, clampingblocks slidably mounted in the radial openings, and a clamping membersurrounding the punch body and engaging the clamping blocks for forcingthem against the punch ins. i

8. A centering punch, comprisinga shank having a punch head at its end,a clamping belt secured to the punch head having a free 'portion formingan annular clamp, a clamping screw connecting the ends of the `treeportion of theclamping belt, a centerpiece fitting Within the clampingbelt and bearing against the end of the punch head, a center pinslidably mounted through an opening in the center of the centerpiece andhaving a head on its end extending into an opening in the punch head.y aspring Ain said opening or', the punch head bearingon t e head of thecenter pin for forcing the center pin outwardly, there being radialopenings in the center piece containing stepped grooves forming seriesof punch pin seats, the respective punch pin seats of each series beingspaced at diiierent distances from the center in andthe correspondingpunch pin seats or" the several series being equi-distant from thecenter pin, clamping blocks htting Within the radial openings andbearing against the punch head and engaged by the clamping belt, punchpins fitting in corresponding punch pin seats of the several series ofpunch pin seats and clamped in place by fthe clamping blocks andengaging the end of the punch head, there being an annular groove aroundthe centerpiece and the cramping blocks, and a'spring retainingbandWithin the annular groove.

in testimony whereof, l afiiX my signa ture, in presence of twoWitnesses.

OSCAR- CHRSTENSOF. Witnesses:

KATHERINE Hom, EMXLY Sorrow/Wma.'

the several series equi-

